{"id":"free-list-head-persisted-in-page-zero","text":"The free list head pointer is stored as the fifth field of the metadata page (page 0) in the layout `[root_page:4B][height:4B][total_keys:4B][next_free_page:4B][free_list_head:4B]`, making it durable across restarts.","truth_value":"IN","source":"entries/2026/05/29/topic-intrusive-free-list-pattern.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"explanation":{"steps":[{"node":"free-list-head-persisted-in-page-zero","truth_value":"IN","reason":"premise"}]}}